Two adult Pachyrhinosauruses greet in 'Walking With Dinosaurs.' / Twentieth Century Fox

by Bryan Alexander, USA TODAY

by Bryan Alexander, USA TODAY

For years, dinosaurs like T-Rex have ruled children's imaginations and movie screens, in films such as Jurassic Park.

Now it's time for Pachyrhinosaurus to lumber into the limelight in the live-action film Walking With Dinosaurs: The 3-D Movie (out Dec. 20).

The film is the big-screen follow-up to the 1999, BBC-produced television series of the same name which won three Emmys, including one for visual effects.

Using even more advanced computer-graphics technology, WWD follows the herbivorous creature known for the large bony frill on its head and its pronounced bumpy nose (its name is derived from Greek for "thick-nosed lizard").

"This is Pachyrhinosaurus' chance to shine. It's an ornate and just phenomenal creature," says paleontologist Scott Sampson, the host and science adviser of the PBS series Dinosaur Train who advised on the film. "A lot of other dinosaurs haven't had the exposure that T. Rex or Triceratops get. So it's nice to see some others become part of the dinosaur iconography."

WWD serves as a window into the latter part of the Cretaceous period, about 70 million years ago and some four million years before Tyrannosaurus rex made its entrance. Don't expect encounters with humans, who hadn't yet appeared.

"If you want to understand the age of the dinosaur, you can not do better than to focus on this time period which we know more about than any other in the entire age of dinosaurs," says Sampson. "So we're able to reconstruct things with more detail. And we watch the dinosaurs do their thing and live their lives."

The film features three Pachyrhinosauruses (Patchi, his brother Scowler and a female called Juniper) living in what is now the Arctic Circle but which then had a temperate climate, similar to Seattle's. It follows the three from hatchlings to adulthood, through the herd's mass migrations and as Patchi becomes the herd leader.

"The issues change from preventing getting stepped on by a massive armored dinosaur or ending up in another dinosaur's gullet, to the males growing up and competing for mates," says Sampson. "So it gives you the scope of the dinosaurs' behavior through their lives."

The story is told with the help of a narrator, Alex, one of the Alexornis birds, which have a symbiotic relationship with Pachyrhinosaurus. This is supplemented with in-the-moment voice-overs from the main characters "as if we are hearing their thoughts," says Barry Cook, who co-directed with Neil Nightingale.

The film has its predatory villain in Gorgon the Gorgosaurus, the smaller-bodied, faster relative of T. Rex with the "powerful jaws full of sharp teeth," says Cook.

Gorgosaurus has many encounters with the tough Pachyrhinosaurus and is also shown attacking the flying reptile Quetzalcoatlus, which has a wingspan similar to a Cessna aircraft.

The filmmakers searched the globe for the right background environment to depict the landscape of the time, eventually settling on Alaska and an island off New Zealand. The computer-graphic dinosaurs were then placed in the scenery and animated.

Sampson says the advanced computer-graphics technology, along with the 3-D images on the big screen, will push the dinosaur action to a new level of close-up realism.

"Jurassic Park set a standard and completely wowed audiences" in 1993, says Sampson. "I truly believe Walking With Dinosaurs is the next quantum leap. It will transport people back in time living with these snorting, hunting, bleeding animals. It's an amazing experience."